Background: Patients with cancer have nearly twice the incidence of suicide compared to the general population. To date, identifying patients at risk for suicide remains challenging. Colorectal cancer (CRC) is the third most common cancer in the US. The purpose of this study was to identify risk factors associated with higher suicide rates (SR) among patients with CRC. Methods: A retrospective analysis was completed using Surveillance, Epidemiology, and End Results data from 1973 to 2014. Comparisons with the general US population were based on US mortality data collected by the National Center for Health Statistics. Suicide incidence, rates and standardized mortality ratio (SMR) were obtained by SEER*Stat 8.3.4. Results: Among 414788 patients with CRC observed for 2785811 person-years, 747 suicides were identified, for an adjusted SR of 26.7/100,000 person-years (SMR 1.40 [95% CI 1.30-1.50]). Higher SRs were associated with male sex, non-white or non-black race, being unmarried and having advanced disease at diagnosis (Table 1). SR was highest in the first year after diagnosis (SMR 2.00 [95% CI 1.68-2.37]) and with increasing age at diagnosis among unmarried patients. In patients 60 to 64 years at diagnosis, SR was highest in unmarried men (SMR 3.72 [95% CI 2.61-5.15]) and lowest in married women (SMR 0.61 [95% CI 0.17-1.57]). Conclusions: CRC is one of the most common cancers in the US. Patients with CRC have a 1.5-fold increase in SR compared to the general population. Suicide screening should especially target those in their first year after diagnosis, particularly older, unmarried patients.